The long term goal of the research project is to develop a theoretical account of the processes underlying classification learning and performance. Specifically, the research focuses on relationships between knowledge of specific exemplars and category level information. Lines of work in the forthcoming year include: 1) assessing the relationship between the number of specific examples used and both the speed of categorization and the liklihood that category-level information will influence judgement, 2) examining the learning and use of correlated attributes within a category, 3) exploring processes associated with recategorization when later information suggests that an instance was initially misclassified, and 4) analyzing the level at which inferences are made as a result of a specific event, instance, or episode being presented. These experiments address some important theoretical and practical issues concerning classification and allow the further development and testing of alternative theories. With a better understanding of the processes involved in categorization we may be able to suggest how to improve human performance in such tasks as psychodiagnosis, disease classification, and x-ray interpretation.